Wiktionary
n. (context physics English) matter which has sufficiently high density that the dominant contribution to its pressure arises from the Pauli exclusion principle.
Wikipedia
Degenerate matter in physics is a collection of free, non-interacting particles with a pressure and other physical characteristics determined by quantum mechanical effects. It is the analogue of an ideal gas in classical mechanics. The degenerate state of matter, insofar as it deviates from an ideal gas, arises at extraordinarily high density (in compact stars) or at extremely low temperatures in laboratories. It occurs for matter particles such as electrons, neutrons, protons, and fermions in general and is referred to as electron-degenerate matter, neutron-degenerate matter, etc. In a mixture of particles, such as ions and electrons in white dwarfs or metals, the electrons may be degenerate, while the ions are not.
In a quantum mechanical description, free particles limited to a finite volume may take only a discrete set of energies, called quantum states. The Pauli exclusion principle prevents identical fermions from occupying the same quantum state. At lowest total energy (when the thermal energy of the particles is negligible), all the lowest energy quantum states are filled. This state is referred to as full degeneracy. The pressure (called degeneracy pressure or Fermi pressure) remains nonzero even at absolute zero temperature. Adding particles or reducing the volume forces the particles into higher-energy quantum states. This requires a compression force, and is made manifest as a resisting pressure. The key feature is that this degeneracy pressure does not depend on the temperature and only on the density of the fermions. It keeps dense stars in equilibrium independent of the thermal structure of the star.
Degenerate matter is also called a Fermi gas or a degenerate gas. A degenerate mass whose fermions have velocities close to the speed of light (particle energy larger than its rest mass energy) is called relativistic degenerate matter.
Degenerate matter was first described for a mixture of ions and electrons in 1926 by Ralph H. Fowler, showing that at densities observed in white dwarfs the electrons (obeying Fermi–Dirac statistics, the term degenerate was not yet in use) have a pressure much higher than the partial pressure of the ions.
Usage examples of "degenerate matter".
The pressure of the blast crushed superheated plasma to the awesome density of degenerate matter, and held the pellet together for the few picoseconds needed to initiate the next stage of the reaction.
The relentless crush of gravity has overcome the mutual repulsion of electrons trapped at its core, shrinking it into a shell of slush around a sphere of degenerate matter.
A robot rocket with huge wings lifted us to orbit, using air compressed nearly to degenerate matter as a propellant.
Heavier than Jupiter, but smaller, much denser, with a degenerate matter core.
In any sane universe, this would set up tidal stresses and tear the ship apart, and we would be just another million kilograms of degenerate matter on the theoretical surface, rushing headlong to nowhere for the rest of eternity or dropping to the center in the next trillionth of a second.
When the guts were scooped out of the star and replaced with a tiny cannonball of cold degenerate matter, the outer layers of the star, held away from the core by radiation pressure, began to collapse inward across a gap of roughly a quarter million kilometers of cold vacuum.
Jinx is the close moon of a gas giant planet more massive then Jupiter, and smaller than Jupiter because its core has been compressed to degenerate matter.
When something stops a byperwave pulse, it's either a stasis box, or it's something denser than degenerate matter, the matter inside a normal star.
It headed straight for the degenerate matter, merged with it unerringly.
The density of the overall mass implies either a control of gravitational forces beyond ours, or use of degenerate matter within the hull.